The SIV Biosafety Level 3 (BL3) Core Laboratory will be directed by Dr. M. Christine Zink. The BL3 technical staff will be responsible for processing all samples from the infected and uninfected control macaques throughout the experiments described in this Program and will provide samples and reagents to all projects in the program. This core laboratory will fulfill the following Specific Aims: To provide expert support in the preparation of SIV and HIV stocks, and quantitation of virus stocks for all projects. To receive, process, aliquot and log into appropriate databases all samples from infected and uninfected macaques. To isolate lymphocytes from blood (and lymph nodes, spleen and brain at necropsy) of uninfected and infected macaques to quantitate and perform longitudinal characterization of the activation and effector state of CD4+/CD8 + and cells and to use these cells in experiments in Projects 1 and 3. To isolate monocytes from blood of uninfected and infected macaques for experimental studies in Projects 1-4. To isolate macrophages/microglia and astrocytes from the brains of all infected and uninfected macaques for analysis for Projects 1, 2 and 4. To aliquot and archive plasma and CSF samples for viral load and other assays. To prepare samples for Real Time PCR, extraction of RNA or DNA for Projects 1 and 2. To process, aliquot and archive blood cells and plasma, CSF and other tissues at necropsy of each macaque in the study as described in the specific projects. To establish primary cell cultures, and maintain cell lines.